99401809 has 4 divisors (see below), whose sum is σ = 107048116. Its totient is φ = 91755504.

The previous prime is 99401807. The next prime is 99401849. The reversal of 99401809 is 90810499.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52780225 + 46621584 = 7265^2 + 6828^2 .

It is a cyclic number.

It is not a de Polignac number, because 99401809 - 2¹ = 99401807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99401807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3823134 + ... + 3823159.

It is an arithmetic number, because the mean of its divisors is an integer number (26762029).

Almost surely, 2^99401809 is an apocalyptic number.

It is an amenable number.

99401809 is a deficient number, since it is larger than the sum of its proper divisors (7646307).

99401809 is a wasteful number, since it uses less digits than its factorization.

99401809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7646306.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 99401809 is about 9970.0455866561. The cubic root of 99401809 is about 463.2315128582.

The spelling of 99401809 in words is "ninety-nine million, four hundred one thousand, eight hundred nine".